Polyamines of xylened amines

ABSTRACT

Polyamines of the formula   AND THE LINKAGES OF THE RINGS ARE META- AND/OR PARA-LINKAG   AND, TO A SMALL EXTENT, ALSO ORTHO-LINKAGES. These polyami   are preferably prepared by desaminating hydrogenation of a   least one of the isomeric m- and p-xylylene diamines,   optionally in admixture with a small amount of o-xylylene   diamine; they are suitable, for example, as modification   components for the preparation of film and fiber-forming   polyamides.   IN WHICH N REPRESENTS A WHOLE NUMBER OF FROM 1 TO 10, PREFERABLY FROM 1 TO 3, R1 represents H or   R2 represents NH2 or   AND THE LINKAGES OF THE RINGS ARE META- AND/OR PARA-LINKAGES AND, TO A SMALL EXTENT, ALSO ORTHO-LINKAGES. These polyamines are preferably prepared by desaminating hydrogenation of at least one of the isomeric m- and p-xylylene diamines, optionally in admixture with a small amount of o-xylylene diamine; they are suitable, for example, as modification components for the preparation of film and fiber-forming polyamides. The rings in the said polyamines may also contain low molecular weight alkyl-substituted groups; this means, of course, that the starting substances for the preparation of the polyamines carry corresponding alkyl-substituents.

United States Patent 1 Hanschke et al.

[ 1 Apr. 3, 1973 [54] POLYAMINES OF XYLENED AMINES [75] Inventors: Ernst llanscbke, Burghausen; Walter Fester, Konigstein/Taunus; Franz Jakob, Hofheim/Taunus, all of Germany [73] Assignee: Farbwerke Hoechst Aktiengesellscbaft vormals Meister, Lucius & Bruning, Frankfurt/Main, Germany [22] Filed: Aug. 19, 1970 [21] Appl. No.: 65,293

[30] Foreign Application Priority Data Tashiro et al., Chemical Abstracts,"Vol. 67, 72996K,

page 6853 (1967).

Hashimoto et al., Chemical Abstracts, Vol. 66, I

l l5108w, page l0679 (1967).

Primary Examiner-Robert V. Hines Attorney- Curtis, Morris & Safford [57] ABSTRACT Polyamines of the formula inwhich n represents a whole number of from 1 to 10, preferably from 1 to 3,

R represents H or R, represents Nl-l or -NHCH2 (H) CHz-NHz and the linkages of the rings are metaand/or paralinkages and, to a small extent, also ortho-linkages. These polyamines are preferably prepared by desaminating hydrogenation of at least one of the isomeric mand p-xylylene diamines, optionally in admixture with a small amount of o-xylylene diamine;

they are suitable, for example, as modification components for the preparation of film and fiber-forming polyamides.

The rings in the said polyamines may also contain low molecular weight alkyl-substituted groups; this means, of course, that the starting substances for the preparation of the polyamines carry corresponding alkyl-substituents.

1 Claim, No Drawings POLYAMINES OF XYLENED AMINES The present invention relates to novel polyamines and to a process for preparing them.

Canadian Pat. No. 837,201 described a process for the preparation of polyamines by means of desaminating hydrogenation of xylylene diamine(s), in which process polyamines are formed, in the molecule chains of which the six-membered rings originating from xylylene diamine are all hydrogenated, i.e. cycloaliphatic. These polyamines are distinguished by a remarkable therrnostability which makes them particularly suitable for numerous application purposes, for example for the modification of film and fiber-forming polyamides and as hardeners for epoxide resins.

ture), advantageously in an amount of from 0.5 to 5 percent by weight, calculated on the starting substances; this nickel catalyst is particularly efficient if it also contains small amounts (up to about 3 percent by weight) of other heavy metals, such as copper, chromium, manganese, or cobalt. lf sucha nickel catalyst containing other heavy metals is used, higher yields of'the desired polyamines are obtained than with a pure nickel catalyst. At a temperature in the range of from 150 to 190C and a hydrogen pressure of from 150 to 200 atmospheres gage a desaminating hydrogenation is taking place, in the course ,of which the polyamines in accordance with the invention are formed. The reaction is stopped as soon as there is a noticeable slowdown in the absorption of hydrogen. This is the case, generally, if about half the amount of hydrogen necessary for the complete hydrogenation of the aromatic nuclei has been absorbed. Depending on the reaction conditions applied within the specified limits, the

process can be performed in such a way that a largely uniform polyamine, or else a mixture of several substances falling under the general formula for the polyamines of the invention, is obtained. The workingup is effected advantageously by means of vacuum distillation, in which process the polyamines are ob- .molecule chains, have, surprisingly, avery good thermal stability. The present invention provides, therefore, novel polyamines of the formula in which n represents a whole number of from 1 to 10, preferably from 1 to 3, R, represents H or and the linkages of the ring are preferably metaand para-linkages.

' To prepare the novel polyamines, at least one of the less suitable; it can also be used, however, in a small amount of at most 10 percent in admixture with mand/or p-xylylene diamine. A nickel hydrogenation catalyst is added to the starting xylylene diamine (mixv weight alkyl groups having from one to five carbon tained as a residue, after the more volatile substances have been distilled off. For some application purposes,

this residue can be used without further distillation; it

can also be separated into its individual components by further distillation.

If in the performance of the above-mentioned process no uniform xylylene diamine isomer has been used as starting compound, the linkages of the rings of the final product are, naturally, not uniform either, but are a mixture of para-, meta-and, optionally, ortholinkages. It is possible to use, insteadofthe unsubstituted isomeric xylylene diamine s,-xylylene diamines that have been substituted preferably bylow molecular atoms.-1n this case the corresponding polyamineshave alkyl substituted benzene. and cyclohexane rings in the chain, instead of the unsubstituted rings in the formula for thepolyamines according to the invention. 1 ;1. y

. It is also possible to prepare the polyaminesofthe in vention in a different manner, for example by using as starting compounds the corresponding qi,ia"- dihalides and ,diamines and, optionally, ammonia. -lThus," for example, I p-xylylene-di(hexa-hydro-p-xylylene)- tetramine can be obtained from p-xylylene dichloride and hexahydro-p-xylylene diamine in a'molar ratio of at least 1 2, according to processes common for reactions of this kind.

The polyamines of the invention are colorless, or at the most slightly yellow, completely liquid substances of a high thermostability. In contradistinctionto the corresponding polyamines which also have aromatic rings in the molecule chains, instead of cycle-aliphatic rings (for example dixylylene triamine), the novel polyamines do not show any signs of discoloration-,nor do they decompose, when heated to about 200C for a limited period of time. This factis particularly surprising, as it was to be expected that the thermal properties polyamines that are completely hydrogenated (i.e. which have exclusively cycle-aliphatic rings), with those of the non-hydrogenated polyamines (i.e. which have only aromatic, but no cyclo-aliphatic rings in the chain). However, the outcome was beyond expectation, since the thermal properties of the partially hydrogenated polyamines of the invention are equal to those of the corresponding completely hydrogenated products which have no more aromatic nuclei in the molecule chain, if the number of amino groups is the same.

The structure of the polyamines of the invention was also confirmed by means of nuclear resonance spectroscopy.

The polyamines of the invention are suitable, for example, as modification components for the preparation of film and fiber-forming modified polyamides in accordance with U.S. Patent application Ser. No. 65,299 filed concurrently herewith, now allowed and entitled: Fiber-forming polyamides with an increased content of amino groups.

The following Examples serve to illustrate the inventron.

EXAMPLE 1 In a 50 liter autoclave provided with stirrer, a mixture was prepared consisting of 20 kg of a mixture of mand p-xylylene diamine in a ratio of 7:3 and 1 percent by weight of Raney nickel, type C of Messrs. Degussa (Le. a nickel catalyst containing chromium and copper); this mixture was hydrogenated at a temperature in the range of from 170 to 190C and a hydrogen pressure of 200 atmospheres gage. In the course of about 3 hours the hydrogen was absorbed very fast. The hydrogenation was stopped as soon as 50 percent of the amount necessary for the complete hydrogenation had been absorbed. After filtration of the reaction mixture, by-products having a low boiling point were distilled off under a pressure of mm of mercury and a sump temperature of 170C, the residue was then kept at 170C for another 1 to 2 hours in order to separate small amounts of colloidially dissolved nickel. The precipitated nickel was filtered off with the addition of activated carbon. The remaining colorless polyamine had a nitrogen content of 14.8 percent, of which 9.0 percent in primary amino groups, 5.7 percent in secondary, and 0.1 percent in tertiary amino groups. This corresponded substantially to the theory for xylylene hexahydro-xylylene triamine. The molecular weight was 275 (theoretical value: 261). It was detected that half of the rings originating from xylylene diamine remained aromatic. The yield of polyamine was 60 percent.

EXAMPLE 2 with xylene, the residue was separated from NaCl by suction filtration, and xylene as well as the excessof the starting diamine, were distilled off in vacuo. The yield of remaining polyamine was 88.2 percent, calculated on the reacted p-xylylene dichloride. The nitrogen content determined by way of analysis was 13.7 percent, of which 6.5 percent originated from primary and 6.6 percent from secondary amino groups. The product did not show any signs of discoloration at 200C. Molecular weight determined: 514 (theoretical value for the molecular weight of p-xylylene-di-hexahydro-p-xylylene-tetramine: 506). I

If in this Example p-xylylene diamine was used, instead of hexahydro-p-xylylenediamine, a polyamine was obtained which did not contain partly cycloaliphatic, but only aromatic rings in the molecule chain.

The product had an amine number of 101 (theoretical value for tetramine: 107) and was thermally instable; it exhibited signs of discoloration and resinified at a temperature of 200C.

What is claimed is: 1. A polyamine of the formula in which n represents a whole number of from 1 to 3,

R represents H or and R represents NH or 

